A temporary clitellum occurs during the breeding season in
(a) Pheretima
(b) Heteronereis
(c) Hirudinaria
(d) Aphrodite

Options

A. Pheretima
B. Heteronereis
C. Hirudinaria
D. Aphrodite

Answer

To solve the question regarding which organism has a temporary clitellum during the breeding season, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Clitellum**: The clitellum is a thickened, glandular section of the body wall found in some annelids. It plays a crucial role in reproduction by secreting a viscid sac that helps in the deposition of eggs.

2. **Identify the Organisms**: The question provides four options:
- (a) Pheretima
- (b) Heteronereis
- (c) Hirudinaria
- (d) Aphrodite

3. **Analyze the Clitellum Presence**:
- **Pheretima**: This organism has a permanent clitellum.
- **Heteronereis**: This organism also possesses a permanent clitellum.
- **Aphrodite**: Similar to the above, it has a permanent clitellum.
- **Hirudinaria**: This organism is known to form a clitellum only during the breeding season, indicating it has a temporary clitellum.

4. **Conclusion**: Based on the analysis, the only organism that exhibits a temporary clitellum during the breeding season is **Hirudinaria**.

### Final Answer:
(c) Hirudinaria

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